New equipment question

[lineout]

Hi everyone,

I have a question regarding two pieces of equipment I'm thinking of buying. I have a a LX-90GPS and am wanting to buy a focal reducer (f/6.3) and barlow lens (2x)

I'm considering Meade but would like any advice you can offer.

Thanks in advance.

[jase]

Welcome to IIS Lineout.

What camera are you using? You want to make sure you don't experience any vignetting with the focal reducer. There are plenty of focal reducers from other manufactures i.e. http://www.optecinc.com/optec_026.htm so shop around.

[lineout]

Thansk for the welcome.

I'm using an EOS 10D. Does the type of camera determine the focal reducer I need?

[jase]

If you have a large format camera i.e. greater the 6mp, I would be cautious. Though this does depend on the chip size. You should be fine with the 10D and the standard Meade F6.3 focal reducer.

[[1ponders]]

Definately don't go for the 3.3 reducer. Your camera chip is too big for this reducer. The 3.3 is designed to be used with smaller chip, dedicated CCD cameras, consequently the outer field of view will look terrible with the Canon chip.

Even with the Meade 6.3 (which is an Ok reducer to start with) you will probably get vignetting at the edges of the camera chip. I did with my 300D on an LX200 8"

[lineout]

Then what focal reducer should I use to eliminate the vignetting?

[[1ponders]]

To fully remove vignetting you would probably need a full 2" FR (even though the meade one says it's 2" it isn't). The other way to help deal with vignetting is to make sure you take flat field shots to use when calibrating your images. It may not be ideal but it is certainly cheaper and you will need to do them anyway to help remove other abberations in your imaging train.

[netwolf]

I dont recall the name but there is an Australian vendor of the Mogg camera adapters that sells focal reducers also. Not sure how good they are but they are an Australian product. Someone can jump in and correct me and put in a link. They are very popular for there Camera adpaters and coolers, I looked at it some time back but I cant seem to find the link.

Regards

[netwolf]

Ok found it
http://webcaddy.com.au/astro/adapter.htm
Regards